Loss from operations increased in the second quarter of 2013 to $18.0
million from $8.1 million in the second quarter of 2012, and to $26.0
million for the six months ended June 30, 2013 compared with $13.8
million for the comparable period in 2012. The increase in loss from
operations for the three and six months ended June 30, 2013 compared to
prior year periods was primarily due to an upfront payment of $10.0
million to Array BioPharma Inc. (Array) in connection with the
initiation of Oncothyreon's collaboration with Array, which was
announced on May 30, 2013. In addition, the increase in loss from
operations for the six months ended June 30, 2013 was also the result
of increased development activity for Oncothyreon's product candidates
and increased general and administrative expenses.

Net loss for the three months ended June 30, 2013 was $16.4 million, or
$0.28 loss per basic and diluted share, compared with net loss of $8.7
million, or $0.15 loss per basic and diluted share, for the comparable
period in 2012. Oncothyreon reported a net loss of $24.7 million or
$0.43 loss per basic and diluted share for the six months ended June
30, 2013, compared with a net income of $1.0 million or $0.02 earnings
per basic and $0.28 loss per diluted share for the comparable period in
2012. The increase in net loss for the three months ended June 30, 2013
compared to the prior year period was primarily attributable to an
upfront payment of $10.0 million to Array, partially offset by a $1.6
million of non-cash income as a result of the change in fair value of
warrant liability for the three months ended June 30, 2013 compared to
a $0.3 million of non-cash expense as a result of the change in fair
value of warrant liability for the three months ended June 30, 2012.
The increase in net loss for the six months ended June 30, 2013
compared to the prior year period net income was primarily attributable
to the upfront payment of $10.0 million to Array, and a $1.3 million of
non-cash income as a result of the change in fair value of warrant
liability for the six months ended June 30, 2013 compared to a $15.3
million of non-cash income as a result of the change in fair value of
warrant liability for the six months ended June 30, 2012. In addition,
the increase in net loss for the six months ended June 30, 2013 was
also the result of increased development activity for Oncothyreon's
product candidates and increased general and administrative expenses.

As of June 30, 2013, Oncothyreon's cash, cash equivalents and
investments were $69.6 million, compared to $83.8 million at December
31, 2012, a decrease of $14.2 million, or 16.9 percent. The decrease
was primarily attributable to $23.9 million cash used in operations
during the six months ended June 30, 2013. This decrease was offset in
part by net proceeds of approximately $9.9 million from the closing of
a June registered direct offering of 5,000,000 shares of Oncothyreon
common stock and warrants to purchase 5,000,000 shares of common stock.

Financial Guidance

Oncothyreon believes the following financial guidance to be correct as
of the date provided. Oncothyreon is providing this guidance as a
convenience to investors and assumes no obligation to update it.

Exclusive of the one-time, upfront payment to Array, Oncothyreon
currently expects expenses in 2013 to be similar to 2012 and cash used
in operations in 2013 to be approximately $29 to $31 million. As a
result, Oncothyreon estimates that its existing cash, cash equivalents
and investments will be sufficient to fund operations for at least the
next 12 months.

Conference Call and Webcast

Oncothyreon will conduct a conference call today, August 6, 2013 at 4:30
p.m. Eastern time (1:30 p.m. Pacific time) to discuss its second
quarter 2013 financial results and provide a review of its pipeline of
products in development. To participate in the call by telephone,
please dial (877) 280-7291 (United States) or (707) 287-9361
(International). In addition, the call will be webcast live and can be
accessed on the "Events" page of the "News & Events" section of
Oncothyreon's website at www.oncothyreon.com. An archive of the webcast will be available after completion of the
discussion and will be posted on Oncothyreon's website.

About Oncothyreon

Oncothyreon is a biotechnology company specializing in the development
of innovative therapeutic products for the treatment of cancer.
Oncothyreon's goal is to develop and commercialize novel synthetic
vaccines and targeted small molecules that have the potential to
improve the lives and outcomes of cancer patients. For more
information, visit www.oncothyreon.com.

Forward-Looking Statements

In order to provide Oncothyreon's investors with an understanding of its
current results and future prospects, this release contains statements
that are forward-looking. Any statements contained in this press
release that are not statements of historical fact may be deemed to be
forward-looking statements. Words such as "believes," "anticipates,"
"plans," "expects," "will," "intends," "potential," "possible" and
similar expressions are intended to identify forward-looking
statements. These forward-looking statements include Oncothyreon's
expectations regarding future expenses, clinical development activities
and the use and adequacy of cash resources.

Forward-looking statements involve risks and uncertainties related to
Oncothyreon's business and the general economic environment, many of
which are beyond its control. These risks, uncertainties and other
factors could cause Oncothyreon's actual results to differ materially
from those projected in forward-looking statements, including the risks
associated with the costs and expenses of developing its product
candidates, the adequacy of financing and cash, cash equivalents and
investments, changes in general accounting policies, general economic
factors, achievement of the results it anticipates from its clinical
trials of its product candidates and its ability to adequately obtain
and protect its intellectual property rights. Although Oncothyreon
believes that the forward-looking statements contained herein are
reasonable, it can give no assurance that its expectations are correct.
All forward-looking statements are expressly qualified in their
entirety by this cautionary statement. For a detailed description of
Oncothyreon's risks and uncertainties, you are encouraged to review the
documents filed with the securities regulators in the United States on
EDGAR and in Canada on SEDAR. Oncothyreon does not undertake any
obligation to publicly update its forward-looking statements based on
events or circumstances after the date hereof.